I wonder how we all survived — and even thrived — in our younger years without the plethora of water bottles that nearly everyone seems to carry around these days.
In reading about the risks and consequences of dehydration, especially for the elderly and anyone who exercises vigorously in hot weather, it is nothing short of a miracle that more of us had not succumbed years ago to the damaging physical, cognitive and health effects of inadequate hydration.
Even with the current ubiquity of portable water containers, far too many people still fail to consume enough liquid to compensate for losses suffered especially, though not exclusively, during the dehydrating months of summer.
For those of you who know or suspect that you do not drink enough to compensate for daily water losses, the good news is you do not have to rely entirely on your liquid intake to remain well hydrated.
Studies in societies with limited supplies of drinking water suggest you can help to counter dehydration and, at the same time, enhance the healthfulness of your diet, by consuming nutritious foods that are laden with a hidden water source. Plant foods like fruits, vegetables and seeds are a source of so-called gel water — pure, safe, hydrating water that is slowly absorbed into the body when the foods are consumed.
That is the message in a new book, “Quench,” by Dr. Dana Cohen, an integrative medicine specialist in New York, and Gina Bria, an anthropologist whose studies of the water challenges faced by desert dwellers led to the establishment of the Hydration Foundation, a nonprofit group that promotes understanding and consumption of nonliquid sources of water.
More about these foods later. First, I must convince more of you that remaining well-hydrated is crucial to your health. However solid your body, the majority of it is water, ranging from 75 percent of the body weight of infants to 55 percent of the elderly. Every bodily process, every living cell, depends on water to function properly. Water transports nutrients, regulates body temperature, lubricates joints and internal organs, supports the structure of cells and tissues and preserves cardiovascular function. People can survive for only three or four days — a week at most — without water.
But more to the point is the quality of survival. Inadequate hydration can cause fatigue, poor appetite, heat intolerance, dizziness, constipation, kidney stones and a dangerous drop in blood pressure. Brain effects include mood shifts, muddled thinking, inattentiveness and poor memory. A loss of only 1-2 percent of body water can impair cognitive performance, according to studies at Virginia Polytechnic Institute and State University. Your body’s water balance is determined by how much you consume, your age and activity level, and environmental conditions. The body loses water through the skin, lungs, kidneys and digestive tract; in other words, by sweating, breathing and elimination of waste, both liquid and solid.
“Water needs can vary from person to person — and no one person will need the same amount of fluid from one day to the next,” the Virginia scientists wrote in the American College of Sports Medicine’s Health and Fitness Journal.
The typical American consumes about 1 liter — a little over 4 cups — of drinking water a day. But people like me who engage in quasi-vigorous physical activity daily need more, and those who exercise strenuously for more than an hour a day need even more than that, perhaps supplemented by a sports drink containing the electrolytes sodium and potassium (but avoid those with more than a pinch of sugar). Keep in mind that skimping on your liquid intake or relying on sugary drinks can take a toll on your physical performance.
If you are planning to engage in strenuous exercise or do physical work outdoors on a hot day, it is best to start hydrating the day before. Check the color of your urine; the paler it is, the better. Also continue to drink water or other fluids throughout your activity and for hours afterward.
A critical factor in remaining wellhydrated is not to rely on thirst to remind you to drink but rather to be proactive by consuming enough liquid before, during and after meals and physical activity. The long-standing advice to drink eight glasses of water a day was something I (among many others) was never able to achieve. I am happy to say that experts have since modified that rule. Current thinking calls for getting about 70 percent of daily water needs from liquids (including coffee and tea, by the way, though not alcohol) and the rest from solid foods.
The authors of “Quench” suggest two dozen fruits and vegetables that are especially hydrating, ranging from cucumbers (96.7 percent water) to grapes (81.5 percent water). Surely you can find many you would enjoy in a list that includes lettuce, tomatoes, cauliflower, spinach, broccoli, carrots, peppers, watermelon, strawberries, pineapple, blueberries, apples and pears.
Even chia seeds, an ancient so-called superfood said to sustain the ultrarunning prowess of the Tarahumara Indians of Mexico, can be a force against dehydration; they absorb 30 times their weight in water and can provide the body with slow-release hydration, especially during long bouts of physical activity in high heat and humidity.
Naturally packaged plant water hydrates more efficiently than plain drinking water, the “Quench” authors maintain, because it is already purified, is packed with soluble nutrients and gradually supplies the body with water.
That said, while there is considerable anecdotal evidence for the effectiveness of plant water, especially among enthusiasts of green smoothies, well-designed clinical studies are still lacking. Yet, I feel comfortable in recommending an increased reliance on these hydrating foods because, at the very least, they can result in a more nutritious diet and foster better weight control.
Getting more of your water from plant foods can also help to cut down on pollution. The earth is being overrun with disposable plastic water bottles that litter streets and parks and float in rivers, oceans and lakes everywhere. Unless you are visiting a region of the world where it is unsafe to drink the water, try to avoid buying water. If you are in doubt about the safety of your municipal water supply, if you rely on well water that has not been tested or if you dislike the taste or your local water, consider installing a faucet filter or using a portable filter container like Brita.
Now, join me as I take a big drink to your health.
Jane Brody is the health columnist for The New York Times.